Method of and apparatus for splicing rubber



Sept. 23, 1952 GE METHOD OF AND APPARATUS FORSPLICING RUBBER Filed Feb. 28, 1950 2 SHEETSSHEET l FIG. I

awe/whoa EVERETT o. GEORGE FIG. 2

ATTOR N EY Sept. 23, 1952 E. D. GEORGE METHOD OF AND APPARATUS FOR SPLICING RUBBER Filed Feb. 28, 1950 2 SHEETS-'SHEET 2 FIG.3

EVERETT D. GEORGE ATTO R N EY Patented Sept. 23, 1952 METHOD OF AND APPARATUS FOR SPLICING RUBBER Everett 1). George, Cuyahoga Falls, Ohio. as-

signor to Wingfoot Corporation, Akron, fihio aicorporation ofDelaware Application'February 28, 1950, Serial.No..146,755

' The present invention relates to a method of and means for minimizing the extent of the; projecting rind or flash of material customarily formed in the splice area in the splicing together of strips of plastic or rubber material. More particularly, the invention is concerned with a process and apparatus for effectively reducing theescape from the splice area of the material being spliced. 7

It is an object of the present invention to provide a method of and means for substantially completely encompassing at least a portion of the 'free ends of the material which are to be joined and exerting uniform compression thereagainst.

It is another object of" the present invention to provide an improved apparatus and procedure which will insure theproduction of a better, more uniform splice in a splicing apparatus.

Other objects and advantages of the improved method and apparatus of the invention will be apparent from the following description of one form of apparatus for the splicing of" rubber tube stockwhich embodies the applicant's inventive concept.

In the drawings,- Fig. 1 represents a partial front elevation of a splicingapparatus which is adapted for use in the trimming and splicing of rubber tube stock in the manufacture of inner tubes for pneumatic tires and illustrates the relation of the machine elements immediately'fo'llowing the trimming operation. Fig. 2 corresponds generally to Fig. 1, but with the machine elements in th'eirsplicing' position andwith parts shown in section and broken away. Fig. 3 is a partial vertical section'taken alongthe line 3-3 in Fig: 1. Fig. 4- is aplan view taken substantially along-the line '4' inFig. 3'. Fig. 5 repre sents'a segment of rubber tube stock in the splice area showing the splice achieved bythe use of applicants teaching. Fig. 6 corresponds generally with Fig. 5, but shows the usual" type of splice obtainedin rubber tube stock.

5 In Figzlofthe drawings the reference numeral r-identifies a splicing apparatus generally. The splicing apparatus l is advantageously employed in the joining together or" the ends of segments bf rubber tube stock for the manufacture of inner tubes for" pneumatic tires, for theiormin'g er endless bands of; tread stock 'for use in the 7 Claims. Cl. '154--9.)

manufacture of pneumatic tires andother articles formed of rubber-brother similarp1a t1 t rials i 'In thesplicingapparatus I. a pair; of knives g2 mounted upon a reciprocatory knife support 3 is employed in trimming the'ends of a segment 4 of extruded rubber tub stock to provideireshlycut, tacky surfaceswhich are adaptedto-be'joined together in a subsequent splicing stepq' To this end, the knives 2 are heatedin-a conventional manner (not shown) to improve the ta'ckiness' of the trimmed ends of the rubber tubestock ii The trimming step is accomplished bylowering the knives 2 into contact with the free ends of the rubber tube stock ewhich are held-in-position by the holding devices don-an anvil 6. Theanvil 5 is moved along a vertical path as by means of the piston rod '2! of. a pneumatic cylinder -(not shown) from the position illustrated in Fiefi l between the carriages 8- to a retracted position therebelow. p p The carriages 8 are mounted on a stationary bed i3 forming part of the-splicing apparatus-l and are capable of movement in a horizontal plane toward and away from each other.: illustrated in Fig. 1 of the drawings, th'ezcar riages 8 are widely "separated during. the trim ming operation. After the anvilt'h'as'been re tracted at'the conclusion ol the trimming operation, the carriagesfljare' moved toward each other to the positions illustrated in Fig. 2, thereby urging the freshly cut tacky free ends .ofjthe rubber tube stock 4 into contact With-each other. This contact is maintained underpres'surejfor a predetermined interval. of timeit'o insure a uniform splice.

One of the essential elements of the holding devices 5 in. thespl'icing apparatus llare' the clamp arms Hl which are integrally/formed witliIslide members It mounted in slidable relationtoth vertically disposedguides l2. v.The mounting. of the slides II. on the. guides 12 .afiords a freedom of movement of the. clamp arms ill-in a' vertical plane toward: and away from the carriagesfil'. it will be understood that the clamp arms [02 are capable of being raisedand'loweredbytheaction of a pneumatic cylinder or; other suitable means (not shown) from the positionsjillustrated' in i 1 to thoseindicated bythedottedlineI-out, lines therein. j A mountingmeans oribra'cket i3- is removably mounted; on each oi" the clamp arms -l'filas means r, a plurality or studboltlsl 1'4 "threaded n o, "a u w ly P ojecting parasite the bracket in such fashionftha't they engage -=the shoulder 15 on the clamp locking see l6-1s provided' on eachlof the studibcltsfl l to insure againstthe unauthorizedl6osenmg, iof the bolts jb operatic" of. the apparatus.'

ment or removal of the brackets l3 from the clamp arms l0.

' On the free end of each of the brackets 13 opposite the slide II is mounted a locating means IT. The locating means H, in each case, is secured in place by a plurality of bolts [8 threaded into the end of the arm Ill. The locating means I! is provided with a hardened plate l9 at the lowermost extremity thereof for registration with a vertically disposed stop element 20 secured in place on each of the carriages 8 as by means of a bolt 2|. Hardened plates 22 corresponding to the plates l9 on the locating means I! are provided on the stop elements 20 so as to cooperate with the plates I9 and to prevent wear when the parts contact each other.

A boss portion 23 which is substantially coextensive with the bracket I3 is formed on the.

under face thereof. Thisboss portion 23 on each of the brackets l3 registers with a groove 24 formed in a clamp member 25 mounted in depending relation to the bracket l3. The mounting of the clamp member 25, in each case, is accomplished by a pin 26 which, as shown in Fig. 2, extends through the bore 21 extending transversely of the groove 24 in the clamp member 25 and registers with a bore 28 in the boss portion 23 of the bracket 13. A suitable bushing 29 is provided in the bore 28 and similar bushings 30 and 31 are inserted in the bore 21 to insure a close fitting relationship of the pin 26 therein. A plug 32 closes the open end of the bore 21 adjacent the bushing 3| therein. A knurled portion 33 on the pin 26 facilitates its removal.

A similar mounting of the clamp member 25 with respect to the bracket 13 is provided on the other holding device to enable a certain freedom of movement in the clamp member 25 in 4 ends of the rubber tube stock 4 will exactly mate when the trimmed tacky ends are brought together. The abutment blocks 38 are positioned on the guide members by means of a pair of locating pins 40 which are press fit into corresponding holes (not shown) in the guide members. The abutment blocks 39 are similarly positioned on the guide members 35 by locating pins 42. Tapped holes 4| and 43 are provided in the abutment blocks 38 and 39 for the reception of a screw jack (not shown) to assist in the removal of the blocks.

In the operation of the splicing apparatus I, it is desirable, as previously indicated, in order to insure a uniform splice for the subsequent vulcanizing operation to have as small a rind or flash portion 44 as possible (see Fig. 5). It is the purpose of the present invention to provide such a splice and to avoid as much overlapping material created by the expansion of the stock as possible as the free ends are butted and jammed together. The splice 45 of Fig. 6 is exemplary of the joint formed in conventional apparatus in which no resistance is offered to the flow or expansion of the material at the abutting faces of the stock in the splice area.

As will be seen from Fig. 3, each of the several elements in contact with the free ends of the rubber tube stock 4 are. provided with a resilient means which takes the form of a sur-.

face or covering of a suitable resilient medium such as the rubber or plastic facings 46, 4], 48, and 49 onthe clamp member 25, guide mem- "j her 35, and abutment blocks 38 and 39, respeceach case, thereby affording careful seli-alignment of the individual clamp members with respect to the ends of the rubber tube stock 4 when the holding devices are approaching clamping position. The pin 26 is capable of being held in place against unauthorized removal by any Suitable means such, for example, as the conventional releasable detent means 34 shown in detail in Fig. 2. V

Cooperating with each of the clamp members 2 5'and also forming part of the holding devices 5 are the guide members 35 mounted on carriages B. The guide members 35 are positioned on the carriages 8 as by means of studs 35, the enlarged heads of which register with the drill holes 31 in the carriage 8 (see Fig. 2). guide members 35 coact with the clamp members 25 to provide a tight grip upon the rubber tube stock 4 adjacent the free ends thereof which are to be spliced together. In order that a uniform splice be obtained, it is essential that these several elements hold the material tightly in place without shifting during both the trimmlng and splicing steps.

The guide members 35 are provided with abutment blocks 38 adjacent their outermost or outboard ends. provided at the innermost or inboard ends of the guide members 35. The abutment blocks 38 and 39 cooperate to locate the ends of the rubher tube stock 4 in the proper positions as the 33 are spaced apart on the uppermost face of the guide members 35 to insure that the free the splice area.

7 hers 25. Similar abutment blocks 39 are tively. Each of theholding devices 5 is so constructed as to insure the provision, through the several facings 46, 41, 48, and 49, of an increased pressure on the splice. and to provide a uniform compressing action which provides an inward pressure on the tube stock at the splice. The cooperative effect of .the facings 43, 47, 48, and 49 of theholding devices 5 is to efiectively seal ofi any outward flow of the stock emanating from This action is clearly depicted in Fig. 2 of the drawings wherein the compression exerted between the facings 43 and 41 of the pairs of clamp members 25 and guide members 35 of the holding devices 5 acts to prevent the expansion of thestock at the free ends of the rubber tube stock 4 when they are mated under pressure. I The rubber in the facings 45, 41, 48, and 49 cooperates with that of the correspondingly numbered facings on the opposed parts to resist or buck the flow of the rubber tube stock 4, thereby producing the greatly reduced rind or flash portion 44 as shown in Fig. 5 and prevent' ing the occurrence of the excessive flash of the type identified by reference numeral 45 in Fig. 6.

To further insure a positive and uniform clamping action upon the ends of the rubber tube stock 4, a plurality of transverse grooves 53 are provided in the under surface of the clamp mem- These grooves 50 coact with a corresponding number of transverse grooves 5| formed inthe uppermost faces of the guide members 35. Other suitableforms of scoring or grooving may be provided to insure against the slippage or shifting of the-ends time rubber, tube stock 4 when intheir proper ositions inthe holding ployed in the treatment and preparation of products fabricated from other forms of plastic material, particularly the heat hardenable plastic compounds, in which case the selection of the composition of the facings 4B, 41, 48, and 49 becomes an important factor. The facings must be formed of such a composition as will produce the desired resistance or bucking action to prevent freedom of flow or expansion of the compound for which the holding devices 5 are designed.

While certain representative embodiments and details have been shown for the purpose of illustrating the invention, it will be apparent to those skilled in this art that various changes and modifications may be made therein without departing from the spirit or scope of the invention.

I claim:

1. Apparatus for mating and splicing together the ends of uncured rubber stock comprising a pair of guide members for supporting and position-ing the ends of the stock to be spliced; a pair of clamp members for urging the ends of the stock against the guide members; a facing of flexible material on each guide member; and a facing of flexible material on each clamp member, said facings being disposed on their respective members adjacent the ends of the stock and coacting when compressed to completely encompass the mated ends of the stock and to resist the fiow of stock in all directions emanating from the splice.

2. Apparatus for mating and splicing together the ends of uncured rubber stock employed in the manufacture of inner tubes comprising a pair of guide members for supporting and positioning the ends of the stock to be spliced; a pair of clamp members for urging the ends of the stock against the guide members; a facing of flexible plastic material on each guide member; and a facing of flexible plastic material on each clamp member, said facings being secured to the ends of the respective members immediately adjacent the ends of the stock and cooperating to completely encompass the mated ends of the stock and to resist the expansion of the stock at the splice.

3. Apparatus for mating and splicing together the ends of uncured rubber stock employed in the manufacture of inner tubes comprising a pair of guide members for supporting and positioning the ends of the stock to be spliced; a pair of clamp members for urging the ends of the stock against the guide members; a facing of vulcanized rubher on each guide member; and a facing of vulcanized rubber on each clamp member immediately adjacent the ends of the stock and cooperating to completely encompass the mated ends of the stock and to resist the expansion of the stock in the splice.

4. Apparatus for mating and splicing together the ends of uncured rubber stock-employed in the manufacture of inner tubes comprising a pair of guide members for supporting and positioning the ends of the stock to be spliced, said guide members being arranged in endw-ise relation to each other; a pair of clamp members which register with said guide members to urge the ends of the stock thereagainst; a facing of vulcanized rubber on the adjacent ends of each of the guide members and on the corresponding ends of the clamp members; and scorings on the adjacent faces of the registering clamp members and guide members for gripping the stock ends.

5. Apparatus of the type defined in claim 4 in which the scorings on the clamp members and guide members comprise a plurality of spaced grooves disposed in opposed relation in adjacent faces of the cooperating clamp and guide members.

6. An improved method of splicing together the ends of uncured rubber stock with a minimum of projecting flash in the splice area comprising the steps of substantially completely encompassing each of the ends of the stock with a compressible material in such fashion that a portion of the stock projects slightly therebeyond; jamming the projecting portions of the stock together in mating relationship with each other; simultaneously therewith bringing the compressible material associated with one of the ends of the stock into contiguous relation with'that associated with the other end of the stock, whereby a body of compressible material is formed surrounding the mated projecting portions adjacent the splice area; and compressing the compressible material around the splice to resist the flow of stock outwardly from the splice area resulting from the pressure applied to the stock ends.

'7. An improved method of splicing together the ends of uncured rubber stock with a minimum of projecting flash in the splice area comprising the steps of securely gripping each of the stock ends; substantially completely encompassing each of the ends of the stock with a compressible material in such fashion that a portion of the stock projects therebeyond; jamming the projecting portions of the stock together while gripping the same to form an end-less container; simultaneously therewith bringing the compressible material associated with one of the ends of the stock into contiguous relation with that associated with the other end of the stock, whereby a body of compressible material is formed surrounding the joined projecting portions adjacent the splice area; and compressing the compressible material around the splice to resist the flow of stock outwardly from the splice in a direction normal to that in which the pressure is applied to the stock ends.

EVERETT D. GEORGE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,027,854 Breth et al Jan. 14, 1936 2,186,286 Engler et al Jan. 9, 1940 2,273,464 Campbell et al Feb. 17, 1942 2,534,252 'Engler Dec. 19, 1950 2,562,540 Engler et a1. July 31, 1951 

1. APPARATUS FOR MATING AND SPLICING TOGETHER THE ENDS OF UNCURED RUBBER STOCK COMPRISING A PAIR OF GUIDE MEMBERS FOR SUPPORTING AND POSITIONING THE ENDS OF THE STOCK TO BE SPLICED; A PAIR OF CLAMP MEMBERS FOR URGING THE ENDS OF THE STOCK AGAINST THE GUIDE MEMBERS; A FACING A OF FLEXIBLE MATERIAL ON EACH GUIDE MEMBER; AND FACING OF FLEXIBLE MATERIAL ON EACH CLAMP MEMBER, SAID FACINGS BEING DISPOSED ON THEIR RESPECTIVE MEMBERS ADJACENT THE ENDS OF THE STOCK AND COACTING WHEN COMPRESSED TO COMPLETELY ENCOMPASS THE MATED ENDS OF THE STOCK AND TO RESIST THE FLOW OF STOCK IN ALL DIRECTIONS EMANATING FROM THE SPLICE.
 6. AN IMPROVED METHOD OF SPLICING TOGETHER THE ENDS OF UNCURED RUBBER STOCK WITH A MINIMUM OF PROJECTING FLASH IN THE SPLICE AREA COMPRISING THE STEPS OF SUBSTANTIALLY COMPLETELY ENCOMPASSING EACH OF THE ENDS OF THE STOCK WITH A COMPRESSIBLE MATERIAL IN SUCH FASHION THAT A PORTION OF THE STOCK PROJECTS SLIGHTLY THEREBEYOND; JAMMING THE PROJECTING PORTIONS OF THE STOCK TOGETHER IN MATING RELATIONSHIP WITH EACH OTHER; SIMULTANEOUSLY THEREWITH BRINGING THE COMPRESSIBLE MATERIAL ASSOCIATED WITH ONE OF THE ENDS OF THE STOCK INTO CONTIGUOUS RELATION WITH THAT ASSOCIATED WITH THE OTHER END OF THE STOCK, WHEREBY A BODY OF COMPRESSIBLE MATERIAL IS FORMED SURROUNDING THE MATED PROJECTING PORTIONS ADJACENT THE SPLICE AREA; AND COMPRESSING THE COMPRESSIBLE MATERIAL AROUND THE SPLICE TO RESIST THE FLOW OF STOCK OUTWARDLY FROM THE SPLICE AREA RESULTING FROM THE PRESSURE APPLIED TO THE STOCK ENDS. 